Manually operable surgical gripping instruments are well known. Typically, the gripping elements located at the distal end of the instrument are operated by movement of a wire or cable manipulated by the surgeon at the proximal end of the instrument. Very often, such instruments comprise a support assembly which includes a thumb hole and a slide which includes a finger grip and is movable with respect to the support assembly. The gripping instrument may be enclosed by a sheath such that when the wire pulls the gripping instrument into the sheath, the gripping instrument is actuated to grasp the tissue. Such gripping instruments are used for purposes such as bronchoscopy, bulboscopy, colonoscopy, duodenoscopy, endoscopy and gastroscopy.
In some situations, relatively substantial movement of the slide with respect to the support assembly is necessary to actuate the gripping instrument. For example, in the case of a polypectomy snare used to surgically remove polyps from the colon, it may be necessary to move the slide relative to the support assembly as much as three and a half inches. This movement, known as the "throw" of the instrument, is very often uncomfortable for the surgeon and sometimes two hands are needed to operate the device.
It is the principal object of this invention to provide a surgical gripping instrument of the type described wherein the throw required to actuate the instrument is reduced.
A further object of the invention is to provide a surgical gripping instrument which is cost efficient to manufacture as a disposable device and which is easier to use than comparable devices by virtue of the reduced throw required to actuate the gripping device.
A still more specific object of the invention is to provide a surgical gripping instrument of the type described which, while providing a reduced throw to actuate the gripping instrument, is similar in appearance and construction to known surgical instruments of this type.